The current recommendations from major health organizations stipulate that if an individual has a BMI in the obese range (>30 kg/m2), they should be counseled to lose at least 5-10% of their body weight. This advice appears to make some sense given that increasing body weight is generally associated with heightened risk of various diseases, and that reduction of body weight usually improves levels of risk factors for disease (e.g blood pressure, triglycerides, etc). However, the literature has been much more complicated in terms of the effect of weight loss on risk of early mortality.
Adding to that literature is a recent study by Ingram and Mussolino published ahead of print last week in The International Journal of Obesity. In essence this recent study showed that weight loss of 15% or more was associated with an increased risk of death from all causes among overweight men and among overweight and obese women.
In the study, a sample of 6117 adults above 50 years of age from the National Health and Nutrition Examination Survey (2888 men and 3229 women) were followed from 1988/94 to 2000.
Quite simply, the authors divided the sample into 3 categories of weight loss (<5%, 5-15%, and >15%) and evaluated the prospective risk of mortality depending on the degree of weight loss, with separate analyses in each gender and even within different BMI categories (normal weight, overweight, and obese).
While that may sound straightforward, the way they ascertained the degree of weight loss is quite a bit more convoluted. First they asked the subjects at baseline: 'Up to the present time, what is the most you have ever weighed? (FEMALES): Do not include any times when you were pregnant.'
They then measured the participants' body weight.
Finally, they calculated the subjects' percent weight loss as:
((maximum weight - baseline weight)/maximum weight) x 100
During the follow-up time, there were 1602 deaths (835 men and 767 women). Interestingly, in contrast to persons with little or no weight loss (<5%, reference category), there was greater risk of early all-cause mortality among those who lost >15% of their maximum body weight, a finding which was statistically significant in overweight men, and in women of all weight categories (normal, overweight, and obese).
While these results may shock some of our readers, similar findings have been reported in numerous other studies. However, many such studies are confounded by various issues making the interpretation of their results rather difficult.
The major caveat to studies ascertaining the relationship between weight loss and mortality risk is delineating intentional (dieting, exercise, etc.) weight loss from unintentional weight loss (loss of body weight due to underlying disease, such as cancer). However, even studies that did separate between intentional and unintentional weight loss have shown conflicting results, suggesting that despite having positive effects on various indicators of health, weight loss may have a negative impact on longevity. Of course, even among those individuals who intentionally lose weight - the methods of doing so can vary widely, with some undertaking dangerous fad diets, extreme exercise or a regular regimen of random and often dangerous diet pills.
In this current study, all analyses were adjusted for age, race-ethnicity (white, black, Mexican-American), cigarette smoking status (current, former, and never), and history of health conditions related to excess weight and/or to weight loss. To try and control for unintentional weight loss, in addition to controlling for pre-existing health conditions statistically, respondents who died within 3 years of the baseline examination were also excluded.
I have yet to see the media catch on to this study, as they have done almost every other time a similar finding is published. Despite the new addition to the literature, the issue of weight loss and mortality is far from being sorted out. The concern is always that our ever increasingly obese population will see such findings as a reason to discontinue healthy lifestyle behaviors, or as a reason to maintain their currently poor lifestyle. It is key to remember that a healthy lifestyle has positive health effects regardless of what happens to one's body weight.
Ingram, D., & Mussolino, M. (2010). Weight loss from maximum body weight and mortality: the Third National Health and Nutrition Examination Survey Linked Mortality File International Journal of Obesity DOI: 10.1038/ijo.2010.41
As long those people whom attempt to lose weight does it in a natural way like a balanced diet or a doctor prescribed regime it should be alright.
Diet pills, weight loss solutions simply don't make the cut. It may reduce your weight for the short-term, but it'll cost you your life in the long term.
Interesting statistics. When I started putting on weight, I began to get health problems such as high blood pressure, so now I'm working hard to shed the weight and get healthy again.
Controlling for intentional vs. unintentional weight loss might not be terribly easy: undiagnosed diabetes was the first thing that popped into my head.
The other problem with controlling a study of this kind is that people who have higher weight loss probably had higher maximum weight and more health issues as a result. There are probably not enough data to bin study participants by maximum weight?
Finally there are all kinds of problems with relying on self-reported maximum weights.
I'll be watching this with some interest: over the past year, I've lost 33% of my body weight (and mainly fat), going from 290lbs to 195lbs. Went from high blood sugars, hyperlipidemia, high blood pressure to...normal blood sugar, great lipid profile, and normal blood pressure, with a resting pulse rate under 60. I'm 52 years old.
If it turns out that I'm more likely to die prematurely now...well, I feel so much better, I wouldn't go back to my old lifestyle. I'm actually working out for the first time in my life.
Loving the blog. Keep up the good work: it's important to a lot of us, and S/N ratio is so low on so many nutrition/exercise/health sites, it's refreshing to find one presenting the actual science.
Good to know, because over the last 3 years I've dropped about 20% of my body weight from maximum (using the calculation in this article) and plan to continue. I'll try to read this paper later. Was there any control for when the people tracked in this research lost the weight (i.e. what age they were at their maximum)?
I'd be very interested to see a breakdown of the type of deaths between the groups--not only could dangerous weight-loss regimes be involved but it could be simple things like people starting to spend more time outside exercising (biking, jogging, and walking on the side of the road is inherently more dangerous than, say, sitting on the couch).
If the rate of just one cause of death (cancer, diabetes, etc). were higher, then that would be medically interesting, but saying that deaths across the board are higher suggests to me some behavioral cause and not a biological one. Is weight loss linked to increased risk-taking behavior?
I agree it would be interesting to see more details: reasons for the deaths, methods of weight loss, rapidity pf weight loss, perhaps the difference between the heaviest people who lost >15% and the lightest people who also lost >15%, or some additional parametric measures to compare.
Did they actually try to separate out the effect of intentional weight loss using diet only and weight loss efforts involving exercise, further subdivided into aerobic/cardiovascular/endurance exercise and resistance exercise?
Diet-only and diet+endurance exercise regimes are well known for inducing loss of significant lean mass along with fat mass, while including resistance exercise in training regimes have mostly prevented this in published studies I'm aware of. My current working hypothesis is that loss of lean mass during weight loss is bad for you but I'm not skilled enough to actually do the work of setting up a prospective study to test this.
@1 I'm not so sure higher weight-loss as a percentage is necessarily linked to a higher starting weight. A 15% weight loss in a 200-pounder would be 30 pounds, leaving him (or her) at 170. That same 15% in someone who starts at 120 gets him/her down to 102. For this reason, segregating intentional and unintentional weight loss might be illustrative. I suspect more people who drop from 200 to 170 did so intentionally than did those who drop from 120 to 102.
Biologically speaking, it is absurd to separate intentional and unintentional weight loss. The body does not care what your wishes are. The physiological response to weight loss is the same whether you urgently wish it, are indifferent, or are unahppy about it.
There are many studies of unintential weight loss. What they show is that weight loss is a late symptom in cancer, occuring only when large tumors are present. The typical patient with unintential weight loss has a GI problem, and regains the weight as soon as the GI syndrome is resolved. Studies of unintential weight loss show how rare it is to find so-called "occult wasting disease" where weight loss is an early symptom of a disease that later proves fatal. "Occult wasting disease" is rare even among people coming to doctors with a complaint of weight loss, and is unlikely to contribute bias to epidemiological studies like NHANES.
I know that taking cues from popular television is fraught with the possibility of error, but I am reminded of a "House" episode in which a patient gets sicker when he fasts because metabolizing fat released a toxin that had built up in his tissues over time.
It makes me wonder if this statistic holds true across various populations with different exposure levels to fat-soluble toxins.
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I've been overweight for a few years now and have been experiencing knee and foot pain, acid reflux, and shortness of breath. My wife and I starting walking every night, I started watching what I ate (and the portion size) AND when I had the option to move or sit down and watch TV, I tried to take the moving option. I've lost 35 pounds so far and feel better than I have in quite a while. My knees and feet don't hurt, the acid reflux has slowed down a lot and the shortness of breath happens only when I really push myself.
I'm still planning on losing a few more, but I'm feeling great. Just had to share.
Yep, as a woman you get a bit envious when you see and hear that men can actually lose weight faster than a man, but that's OK. As long as we all watch what we eat and get our bodies moving as often as we can, we'll all be healthier.
Being overweight and obese can lead to SO many health problems that we all need to do what we can to prevent it.
Why is it that I'm shocked at the prospect of an early death because of making an attempt to change your life for the better? For example, an overweight person finally decides to make a positive change in their physical body by ridding themselves of excess weight only to find that they could possibly be setting themselves up for an exit from this planet a bit sooner than thought?
I'm fascinated and will not only follow this as closely as possible but will definitely let my clients in on this and ask them to follow your posts as well.
It seems our society hates fat so much that it is almost impossible for many to accept that it might actually have health benefits is some cases. This is the bias of our particular era and culture. We have been taught to see fatness and ill health as synonymous. A hundred years ago, the opposite was true - fatness was seen as a sign of health and wellness. The change in perception has to do with many factors, including the over abundance of food in western countries. Now that everyone has more than enough to eat in western countries, thinness has become the symbol of status and curiously (or not) wellness. It is probably the case that neither fatness nor thinness consistently confer good health. Possibly taking regular exercise and eating reasonably well is a good thing though!
In the context of these kinds of studies, Glenn Gaesser and Steven Blair's research is relevant - they have done studies showing that most people can eliminate all the health problems normally associated with overweight or obesity by being physically active and eating well, even when they don't lose any weight.
In fact they question the link between overweight and ill health. Being overweight correlates to some health problems but seems not to cause the problems. High blood pressure, diabetes, etc are probably caused by lack of exercise and poor diet. And indeed many fat people are inactive and eat badly. However many "normal" weight individuals also eat poorly and don't exercise and have these same health problems.
There are probably some good reasons why weight loss is bad for health - human beings did not evolve a mechanism to lose weight, since we have almost never lived in environments where weight loss had any benefit. This may be why wieght loss is so difficult to maintain, and why it adversely affects our longevity.
Whoa! This is disturbing! And we thought coming down from 100 pounds to 30 in a jiffy was a godsend gift! Sounds it is more a proposition for death as per your Blog post! Well written information - and very well supported through evidence as well. Need to keep a strict watch on those weight supplements from now on! LOL..
There are proper ways to lose weight even though it may take some time to take effect. Those methods claiming to be the fastest may not be safe at all, which is why they're associated with with early mortality.